Piston and connecting rod
- 1. Piston rings
- 2. Piston
- 3. Piston pin
- 4. Retaining ring
- 5. Connecting rod
- 6. Connecting rod bush
- 7. Cylinder block
- 8. Connecting rod cap
- 9. Locating pin
- 10. Oil jet
- 11. Oil jet screw
- 12. Connecting rod cap bolts
- A - identification marks on the connecting rod and connecting rod cap
- B - orientation marks
Piston and connecting rod
Withdrawal
1. Remove the cylinder head, flywheel, oil pan, oil pump and oil pickup pipe.
2. Remove the shoulder at the top of the cylinder due to wear.
3. If the connecting rods and connecting rod caps are not marked, mark them.
4. Set pistons N1 and N4 to bottom dead center.
5. Unscrew the fixing nuts, and remove the cover of the first connecting rod and the bearing shell, mark the liners.
6. Put pieces of rubber tube on the connecting rod bolts so as not to damage the crankshaft journal and cylinder walls.
7. Remove the bearing shell and remove the connecting rod from the top of the cylinder block.
8. Remove the rest of the connecting rods and pistons in the same way.
9. If possible, unscrew the screws and remove the piston jets.
Piston head (AAT)
Examination
1. Use a small screwdriver to remove the piston pin circlips and remove the pin. Inspect the finger for wear and damage, if damage is found, contact a specialist.
2. Remove piston rings. Clean the piston head from deposits and clean the grooves for the piston rings. After removing all deposits. Clean pistons and connecting rods with solvent and dry them.
3. Carefully inspect all pistons for cracks in the piston skirt and around the connecting rod pin. Inspect pistons for scratches, nicks, burnt areas, or corrosion.
4. Inspect the connecting rods for cracks or other damage. For a more detailed verification of pistons and connecting rods, contact the specialists
5. Measure the diameters of all four pistons.
6. Measure the backlash of the piston rings.
7. When assembling the piston and connecting rod, note that the arrow on the piston head must point towards the timing belt. The marks on the connecting rod and on the connecting rod cap must face the same direction as the turbocharger.
Checking the lubrication clearance of connecting rod bearings
An internal micrometer or other special device can be used to measure the lubrication gap, but the most accurate and easiest method is to use a special plastic gauge.
Temporarily install the piston in the cylinder, tighten the connecting rod cap bolts, and check the connecting rod bearing lube clearance in the same way as checking the main bearing lubrication clearance.
If the clearance is not correct, the wrong size bushings may have been installed.
Piston arrangement and coding in diesel engines
Final installation of pistons and connecting rods
1. Remove all traces of plastic. Check that the surface of the bearings is absolutely clean and lubricate them with engine oil.
2. Clean the upper connecting rod bearing and install it on the connecting rod. The lubrication holes of the connecting rod and bushing must be aligned.
3. Clean the second bearing and install it in the connecting rod cap.
4. Lubricate the pistons and rings and compress the piston rings with a piston ring compressor.
5. Rotate the crankshaft so that the connecting rod bearing of the first cylinder is in the bottom dead center position, and lubricate the cylinder walls.
6. Check that the mark on the top of the piston is facing forward.
7. Press down on the piston and install it into the cylinder.
8. The rest of the connecting rods are installed in the same way.
9. Install the connecting rod on the shaft journal and install the connecting rod cap.
- A - pin (diesel only)
- B - mounting hole (diesel only)
10. In diesel 4-cylinder engines 1Z and AHU and 5-cylinder ABP, AAT, AEL pistons have a special shape for better combustion of the mixture and must be correctly installed (see fig. Piston arrangement and coding in diesel engines).
11. Tighten the bolts to the required tightening torque.
12. Tighten the bolts to the required angle.
13. After installing all the connecting rods, rotate the crankshaft several times and check for ease of movement.
Diesel engines 1Z, AHU, AAS, ABP, AAT, AEL
13. To accurately select the thickness of the gasket, measure the protrusions of the pistons using a special tool.
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